1. Field of the Invention
The present invention is related to a method of providing interactive text response services, and more specifically, to a method of providing DTMF-based interactive text response services.
2. Description of the Prior Art
Dual-tone multi-frequency (DTMF) signaling is an in-band telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers for identifying the number dialed by a user. DTMF signaling involves a high frequency group and a low frequency group each including 4 audio frequencies. One audio frequency from the high frequency group and one audio frequency from the low frequency group are transmitted in pairs to represent one of 16 DTMF signals corresponding to the digits, letters or symbols dialed by the user.
Interactive voice response (IVR) is a value-added service based on the existing DTMF telecommunication system. Originally implemented on phone servers, IVR allows a user to control a user interface by voice commands or keypad commands. For example, many banks, credit card centers or telecommunications service providers offer an interactive voice response system (IVRS) so as to provide automatic phone inquiry services. After dialing the designated number, a customer may enter the system. After selecting an appropriate option or inputting personal information according to system instructions, the customer may access pre-recorded messages or specific data (such as account balance or credit card bill), or perform certain transactions (such as making a money transfer, changing personal password or changing contact details).
In mobile communication applications, multiple channels are established between a mobile device and a base station. In GSM (Global System for Mobile Communications) systems as an example, voice channels and digital channels including fast associated control channels (FACCHs) are established between a mobile device and a base station. When a user pushes a button of the mobile device, corresponding DTMF data is transmitted from the mobile device to the base station, which then generates and sends a corresponding analog voice message to a receiving device so as to respond to user commands.
In a prior art IVR system based on existing DTMF structure, when a user dials the number designated by a specific institution, the specific institution may reply a voice message via the receiving device. However, the user may not be able to memorize all contents of the voice message and thus need to replay the voice message or record the content of the voice message. Therefore, there is a need for method of providing DTMF-based interactive text response (ITR) services.